The electric field monitoring is of great significance. According to the characteristic laws of the change in atmospheric electric field, intensity of the electric field in a space region or around equipment is monitored by an electric field sensor, which has very important applications in such fields as aerospace, national defense, smart power grids, weather, and industrial production or the like. With the monitoring of the change in the atmospheric static electric field close to the ground and in the air by the electric field sensor, accurate weather information can be obtained, so as to provide important security assurance to launch of aircrafts such as guided missiles and satellites or the like, or provide lightning early warning, forest fire prevention, earthquake prediction or the like.
With the rapid development of micro/nano machining technology and integration technology, the development of a new type of electric field sensor with a small size, low power consumption, and easy mass production becomes an interesting research direction in the field of electric field detection technology. Due to the outstanding advantages such as a low cost, a small size, low power consumption, feasible mass production, easy integration, a wide operating frequency band, and a high spatial resolution for electric field detection, the micro/nano technology based micro electric field sensor gradually becomes one of devices for electric field detection having important development potentials, and gets more and more attention from researchers in the world.
However, in practical applications, micro electric field sensor sensitive chips are susceptible to the influence of the dust air, airflow, rain and snow, and high humidity or the like and thus cannot operate properly. Therefore, packaging is an important challenge for practical applications of a micro electric field sensor. The micro electric field sensor is easily affected by external environment factors due to its small size and weak signal. There are many ways for packaging micro sensors, for example packaging schemes such as using a pure metal sealing cap, arranging a hole in an upper surface of a metal cover or the like. However, in the former case, the electric field is shielded due to a metal cabin formed by metal and a substrate, and in the latter case, it is difficult to achieve effective packaging due to failing to block humidity, dust or the like from entering the metal cabin.